Rotary underreamer



BEST AVAILABLE COPY March 30 1926. V

J. M. BATEMAN ROTARY UNDERREAMER' Filed April 4, 1923 iiiiiii Joim M i A TTORNE Y.

Patented Mar. 30, 1926.

U ITED STATES JOHN M. BATEMAN, OF LONG BEACH, CALIFORNIA.

ROTARY UNDERREAMER Application filed April 4.

To all whom it may concern:

Be it known that I, JOHN M. BATEMAN, a citizen of the United States, residing at" Long Beach, in the county of Los Angeles and State of California, have invented a new and useful Rotary Underreamer, of which the following is a specification.

This invention relates to rotary underreamers such as used in sinking oil wells for cutting in the bore of a well below the shoe or lower end of a. casing. The--general: object of the invention is toproduce an underreamer of simple construction which; so constructed that it can readily pass down the casing, but which will automatically ex- I pand and place its cutters in proper relation for cutting in the bore of the wellfbelow the casing; also to provide a device of this" kind which will automatically fold orhouse, the cutters in the body in the underreamer in the movement which withdraws the underreamer upwardly into the casing; also to construct a device of this kind in such a way as to insure that a liberal supply of water will be delivered to the cutters in the proper direction; and to construct the device so as to insure that the muck from the cutters will drain from the working parts so as to prevent their becoming clogged or rendered inoperative. Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an eflicient underreamer.

A preferred embodiment of the invention is described in the following specification while the broad scope of the invention is pointed'out in the appended claims.

In the drawing: I

Figure 1 is a vertical section through an underreamer embodying my invention.

Fig. 2 is a side elevation of the underreamer partially broken away.

. Fig. 3 is a cross section through the underrcamer taken on the line 33 at Figure 2.

Fig. 4 is a view similar to Figure 1 but showing the relation of the parts when the underreamer is being withdrawn upwardly into the casing after an underreaming out has been taken.

Fig. 5 is aside elevation of the underreamer showing a side face not illustrated 1923. Serial No. 629,849.

in Figure 2; this view is upon a much reduced scale.

Fig. 6V is a cross sectlon taken on the line 6+6. in Figure 4.

Fig. 7 is a side elevation illustrating the .details of one of the cutter arms. g

line 2 passing through the body. U Within this body I mountmovably a tool but preferably a pair of tools which have cutting edges and which are capable of shifting upwardly in the body to. an elevatedposition.

In the present instance each toolcomprises a tool carrier in the form of an arm 3 and edges of the cutting members or disc 4'. out

wardly beyond the periphery of the body. In order .to accomplish this in asimple manner, I construct the arms 3 of rectangular cross section and mount each arm to slide in a corresponding groove 5 in the abuttmg face of its corresponding body section. Any sultable means may be provided to effect the expansion or outward swinging movement of the arms as they reach their elevated position. For this purpose I may simply provide a cam face 6 at the upper end of each groove 5 which will be struck by the upper end of the arm so as to deflect the arm outwardly, and beyond this cam face 6 I provide an outward thrust face 7. Opposite to the thrust face 7 the groove 5 is widened out and presents aguide face 8 parallel with the face 7 so that the upper end of the groove 5 virtually forms a socket or square notch 9 into which the upper end of the arm 3 projects when the arm is in its elevated position. WVith the arms inthis position it will be evident that the cuttors will project beyond the periphery of the body and when they are rotated the cutters quately receive. this thrusts.

'nected directly together by a pivot pin,

will cut inthebore of the well at about the point 10 indicated inFigiire 1. Therefore; the thrust on the tool from thecutting will be exerted against thetaceJTwhich will ade= The means for forcing the cutters into their expanded position is preferably in the form of .a. coil spring '11 disposed around a stem 12 carrying a shoe 13 at its upper end, which engages the rounded lower ends of the arms or levers 3. The lower end of this spring sets against a bushing 14 screwed into the lower end of a bore 15 which constitutes a spring barre'l.: This bushing is formed with an opening 16 so that any mudor water coming down through the spring barrel 15 will drain out. In-*addition. to this, guide grooves 5 are provided with drain openings;

but I prefer to mount them so that they are not held in an exactly vertical planefbut slightly inclined .(see Figure 2). There is just suflicient clearance bet-ween the upper edges of the cutters to enable them to swing in and out and each cutter is provided with a central opening 19 which is received upon a hub 20 which projects inwardly from the upper end of the arm (see Figure 7). The axis of this hub or stud inclines sli htly downwardly, but the end face 21 of thishub is in a vertical plane. The arms are mounted in place in such a way that the face 21 of one hub will engage the corresponding face 21 of the opposite hub and this-engagement may be maintained even when he cuttei's have been expanded (see Fi e- This arrangement prevents pressure coming upon the discs t'hemselres, which would tend to bind them and'prevent their rotation. In other words, the thicknessof the'cutters is slightly less than the length of the hubs,'so

that clearance is provided for their free rotation. These discs may have any desired cross section, for example, such as that shown in Figure 3, in which the direction of the rotation would be clockwise.

The. lower ends of the arms 3 may be con- 0-) q but this pin preferably does not pass complctely through the arms, but is received in a socket .23 in the inner taco of each arm (see Figurel).

As illustrated, the body is preferably formed of two parts 1 and l and in order to facilitate alinement of these sections in putting the same together the. meeting face of one of the members, for example, the member 1", is provided with a pair of dowel pins 24 which are received in corresponding addition to this, I provide two bolts 25, the

heads and nuts of which are countersunk into recesses 26 see Figure 2).

The upper end of the body may have the usual threaded connection to a drill collar 27 (see Figure 1). V

In order to provide an ample water supply to the cutters, I provide two drilled passages or ports 28 passing down from the upper end ofgthe body As viewed in Figure 2, these ports are inclined toward the central plane 2 of the body and as viewed in Figure 1 they incline in an outward direction, that is to say, they should deliver the water through the upper face 29 of the central slot 18 and in an outwardly inclined direction so asto project the water against th dished face otthe cutter. is this water will undoubtedly tend to carry muck and dirt down into the spring barrel and into the vicinity of the shoe 13, attention is called'to the opening 17, which will permit the same to find exit.

My object in inclining the cutters as described is to cause them torotatc automatically as they cut. This insures that the cutting .will be distributed along the entire periphery of each disc and produce a sub stantially uniform wear. It also prevents a straightportion from being made on the edge of the cutter which might tend to preventits rotation.

In withdrawing the underreamer it will be evident that after the same is pulled up wardly through the shoe indicated in dotted lines at 30 in Figure 4, the thrust of the inclined face 31 of the shoe against the upper portion and side of each disc will cause a downward movement of each cutter relative to the body and will shove the .arms 3 more or less down 'ardly in their guide grooves 5. upperv end of each arm from the out thrust bearing face and thisv will permit the arms to slide along the cam faces 6 and fold inwardly in the manner indicated in Figure 4.

In lowering the underreamer through the casing it will be evident that as soon as the cutters pass below the lower endof the shoe the spring 11 will operate to force the arms 3 upwardly until their upper ends seat in the notches 9. Attention is called, however, to the fact that when the cutters are in' opcrat ion, the thrust duo to means were used to produce a slight projection of the cutters beyond the periphery ol Inn This, of course, will dislodge the llU down

the body because as soon as the cutters be in I to cut they will immediately force the arms 3 upwardly and seat them in their socket 9.

T a body, a pair of tool-carriers movably In other words, the spring is a desirable adjunct to insure perfect and reliable operation of the device.

It is understood that the embodiment of the invention described herein is only one of the many embodiments this invention may take and I do not wish to be limited in the practice otmy invention nor in my claims to the particular embodiment set forth.

\Vhat I claim is 1. In an underreamer, the combination of a body, a pair of tool-carriers movably mounted in the body so as to be capable of shifting upwardly in the body, a cutter disc carried by each tool-carrier and disposed in a substantially vertical plane so as to roll down the inner side of the casing, a spring for shifting the tool-carriers upwardly and operating to hold the edges of the discs against the casing when the underreamer is being lowered within the casing, said body having means cooperating with the toolcarriers in the upward shifting movement eilected by the spring after the cutters pass out of the lower end of the casing, to project the upper ends of the tool-carriers outwardly with the edges of the discs projecting beyond the periphery of the body and beyond the casing.

2. In an underreamer, the combination of mounted in the body so as to be capable of shifting upwardly in the body, a cutter disc carried by each tool-carrier and disposed in a substantially vertical plane so as to roll down the inner side of the casing, a spring for shifting the tool-carriers upwardly an operating to hold the edges of the discs against the casing when the underreamer is being lowered within the casing, said body having means cooperating with the toolcarriers in the upward shifting movement efi'ected by the spring after the cutters pass out of the lower end of the casing, to project the upper ends of the tool-carriers outwardly with the edges ofthe discs projecting be yond the periphery of the body and beyond the casing, said body having out-thrust faces to co-operate with the tool-carriers after the underreamer has passed out of the casing to resist the thrust of the .discs when cutt ng.

3. In an underreamer, the combination of a body, a pair of tools supported near their lower ends having cutting edges and mounted so as to be capable of shifting bodily upwardly in the body to an elevated position, means extending longitudinally of the body for guidingthe tools in the said upward shifting movement operating to move the upper portion of the tool outwardly and project the cutting edge beyond the periphery of the .body, said guiding means having an extension with an outthrust face corresponding to each tool and co-operating with its corresponding tool in its elevated position to resist the thrust upon the tool in cutting.

4. In an underreamer, the Combination of a body, a pair of tools, each tool having an arm with a cutting member disposed toward its upper end and mounted so as to be capable of shifting upwardly in the body to an elevated position, and means including a socket in the body to receive the upper end of each arm when in its elevated position and cooperating therewith, so as to project its cutting member beyond the periphery of the body.

5. In an underreamer, the combination of,

6. In an underreamer, the combination of.

a body, a pair of cutting tools consisting of two arms pivoted adjacent their lower ends so as to be capable of swinging outwardly at their upper ends, a cutting member carried by each arm. said body having guideways extending longitudinally within its interior cooperating with the arms to project the upper ends of the arms outwardly when the same are shifted upwardly to project the cutting member beyond the periphery of the body and resist the thrust on the tool in cutting.

7. In an underreamer to be passed down through a well casing, the combination of a body, a pair of cutting tools consisting of two arms bodily movable upwardlyv in the saidbody, and pivoted together adjacent their lower ends so as to be capable of swinging outwardly at their upper ends, and a cutting member carried by each arm, means on the body for engaging the upper ends 01 the arms to project the same outwardly when shifted upwardly to project the Gilt ting member beyond the periphery of the body, and a spring within the body for forcing the arms toward their upwardly shifted position, said spring operating to yield'when the cutting members engage the shoe or casing in the withdrawing movement and thereby permit the arms to fold inwardly to withdraw the cutting members into the casing.

8. In an underreamer, the combination of I a body havi1ig a transverse slot,'a pair of arms pivoted together at their lower ends, said body having a guide groove for each of said arms. a spring mounted in the body exerting its force in a direction to move the arms upwardly in the body, a rotary cutter carried by each arm, the upper end of each groove having a cam face to co-operate with the upper end of the arm when the same is moved upwardly to force, the same outwardly so as to project the edges of the cutters from the slot and beyond the periphery of the body. c

9. In an underreamer, the combination of a body having a transverse slot, a pair of arms pivoted at their lower ends, said body having a guide groove corresponding to each arzndor guiding the same in an upward direction in the body, a shoe engaging the lower ends of the arms and having a stem guided in the body, a spring around the stem and forcing the shoe against the arms in a direction to move the same upwardly in the body, said body having means for moving the arms outwardly in the slots and difierent directions from each other, and cutters carried by the said arms and constructed to project from the slot and beyond the periphery of the body when the arms have been forced upwardly,

10. In an underreamer, the combination of a body, a pair of arms pivotedtogether at their lower ends, means for guiding the arms on the body to move bodily upwardly, a spring exerting its force on the arms in a direction to move the same upwardly, said body having means for guiding the arms outwardly when moved upwardly, and cutters carried by said arms constructed to project beyond the periphery of the body when the arms have been moved upwardly,

' said body having out-thrust bearing faces to correspond with the arms and receiving the thrust or the cutters when in operation.

11. In an underreamer, the combination of a body, composed of two sections having abutting faces in the central planejot the esteem body, a pair of armsmounted to move vertically up and down therein, said body having guide grooves in the said abutting faces extending iongitudinally of the body, and receiving the arms for moving the arms outwardly when they are moved upwardly, and cutting members carried by the arms to project beyond the periphery of the body when the arms have been moved upwardly.

12. In a rotary cutter, the combination of a body, a pair or" members mounted tobe shifted longitudinally in the body, cutting discs carried respectively thereby, means 150- operating with the members to move the same outwardly when shifted longitudinally in the body, said members having hubs projecting toward each other, each hub rotatably supporting one of the discs, the end races of said hubs engaging each other and preventing binding of the discs and enabling the same to rotate freely on the axes of the hubs when in operation.

13. In a rotary cutter, the combination of a bodyga pair or" members mounted to be shifted longitudinally in the body, cutting discs carried r spectively 1 thereby, means cooperating with the members to move the same outwardly when shifted longitudinally in the body, said members havmg hubs projecting toward each other, each hub having its axis inclined and rotatably supporting one of the discs in an inclined position, the end faces of said bubs engaging each other and preventing binding of of the discs and enabling the same to rotate freely on the axes of the hubs when in operation.

Signed at Los Angeles, California, this 27th day of March, 1923.

JOHN M. BATEMAN. 

